The present invention relates to a connection fitting for effecting a connection to a tube, e.g. to connect the tube to one or more other tubes. The invention is particularly related to fittings for connecting small-diameter tubing (e.g., up to 16 mm) adapted to carry relatively low air or liquid pressure (e.g., from 2.5-4 atmospheres).
A large number of fittings are now in use for making tube connections. One common type includes a steel grab washer between the cap and body member of the fitting and effective, upon tightening the cap onto the body member, to bite into the tube and thereby to retain it within the fitting. Such a fitting, however, does not permit the ready removal of the tube should it be desired to detach it from the fitting. In addition, such fittings usually accommodate only one tube size and therefore require a separate fitting size for each size tube to be connected. Further, such fittings usually also require separate sealing means, such as gaskets or sealing rings, to prevent leakage of the fluid carried thereby.
It is also known to use a connection fitting including a cap threaded onto a body member, which cap is formed with a plurality of resilient fingers adapted to engage the end of the tube to securely clamp the tube within the body member. However, such known fittings also usually require separate sealing means; moreover, they usually also can accommodate only one size tube and therefore require a special size fitting for each size tube.
An object of the present invention is to provide a connection fitting having advantages in the foregoing respects. More particularly, an object of the present invention is to provide a connection fitting of few and simple parts which not only securely locks the tube within the fitting in such manner as to permit its ready removal should it be desired to detach it from the fitting, but which also effectively seals the tube within the fitting, and which also accommodates a range of different-sized tubes so that one fitting can be used for several different-sized tubes.